A restricted architecture network is used, for example, to provide entertainment or other services to passengers on board an aircraft, commonly referred to as an in-flight entertainment system (IFES). In an IFES, a plurality of computers are connected to provide various functions. These computers include, for example, audio/video headend equipment, area distribution boxes, passenger service systems (PSS), and seat electronic boxes. In the modular environment of a restricted architecture network, each of these computers is referred to as a line replaceable unit (“LRU”). At least some of the LRUs act as client devices serving passenger seats individually or by seat groups to display video entertainment or instructional presentations, to receive input for selection of audio/video or PSS choices, to provide telephony or communication capabilities, to play interactive games, or to provide other similar kinds of services.
When a plurality of computers are run within a restricted architecture network, such as within an IFES, it is absolutely necessary for the software configurations on each of the respective computers to be maintained according to exact specifications. The software configuration, including an exact number of identifiable software components, must be maintained: all of the software components specified as part of the software configuration must be present; no software components not specified must be present. Proper IFES maintenance requires the checking of the software configurations of the various LRUs within the restricted architecture network and the subsequent downloading of software to the LRUs to update available selections and services or to diagnose and fix any problems.
Restricted architecture networks, thus, have serious constraints on their structure and function. Such a network usually has a limited amount of physical space available for the hardware and connections between discrete hardware components. The amount of power or bandwidth for connections available may be limited. The origin of these constraints, as well as the need for absolute consistency in software configuration within the restricted architecture network may arise from the requirements placed on such systems by external agencies, such as the Federal Aviation Administration (FAA). The FAA requires, for example, that only thoroughly tested software configurations be allowed to run within a restricted architecture network. The risk that an LRU with a slightly different software configuration might disable the function of the entire network, or of flight computers on the aircraft, is too great to allow a single discrepancy. Thus, a method for configuring LRUs within a restricted architecture network must be perfectly consistent and reproducible; but maintaining near perfect consistency often requires an expensive, labor intensive method.
The time availability for conducting IFES hardware and software maintenance is also limited to the short maintenance window between flights as a plane sits at a gate for unloading and loading. The software configuration of each of the computers within the IFES system must be setup and tested during this limited maintenance time window. In practice, if the IFES configuration and download method exceeds the otherwise scheduled maintenance period, operators will avoid initiating or abort the IFES maintenance. As a result, it is desirable to optimize the speed and efficiency of the method of configuring and downloading software to computers in an IFES. In conventional systems, during hardware installation, e.g., during the removal or addition of a seat electronics box, software cannot be updated or configured—the entire hardware configuration must be in place before software configuration can be begin. Accordingly, the required service time has been the time for hardware configuration plus software configuration. The time window of opportunity to perform such a service task while a plane is on the ground is very limited.
Maintenance personnel are expensive overhead for an airline. In order to minimize the number of required IFES maintenance personnel, and to minimize the required training and skill level for conducting basic IFES maintenance tasks, it is desirable to provide an IFES configuration and download method which is reproducable and reliable.
Conventional methods and systems for maintaining the software configuration on the plurality of computers within an IFES are not usually implemented in a network, and are based on the use of a “master” computer, hard-wired to other computers within the system, which polls each “slave” computer for its current configuration, tabulates a list of the software configuration on each computer, and downloads to or deletes from a particular computer the necessary software components.
The downloading, deleting or overwriting of software components has been conventionally performed in a sequential manner, software component by software component. Each computer must wait for each of a series of missing software components to be downloaded, one at a time. The conventional configuration method is initiated, for example, when an operator selects a particular software component to be downloaded to the plurality of computers within the system. Conventionally, the master computer downloads the selected software component in a sequential manner to a first slave computer, then to a second slave computer, then to a third slave computer, and so on. Furthermore, the IFES configuration and download method conventionally operates in a completely serial manner among the IFES computers, i.e., the master computer connects only to one slave computer at a time, and downloads only one software component to that slave computer at a time.
The conventional serial and sequential downloading techniques have impaired the development of IFES systems, as each additional computer or configurable software component increases the required maintenance time and method complexity, thereby increasing the possibility of system error and failure. At present, an IFES might consist of close to one thousand separate, configurable computers, each with a software configuration that must be perfectly maintained. The exceptional difficulty of accomplishing this task as the number of LRUs within a restricted architecture network multiplies makes it desirable to provide a configuration checking and software downloading method that operates in a parallel manner. More particularly, it is desirable to provide a system and method wherein a master computer connects to more than one slave computer at a time or downloads more than one software component to a slave computer at a time.
A conventional IFES has operated on custom, proprietary software and hardware, including proprietary protocols for signal transmission within the IFES network. Due to a complex and unique nature of such proprietary systems, problems in the IFES have been difficult to diagnose and fix.
As a result, a need exists for an improved method and system for configuring the software of a multi-computer system within a restricted architecture network.